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United States Patent |
5,521,680
|
Young
|
May 28, 1996
|
Printer having a self-aligning charging device
Abstract
An automatically self-aligning charging device assembly for producing a
layer of charge on a charge holding surface in alignment with a document
registration position on the platen of a machine. The assembly includes a
charging element having a start-of-charging position thereto, and a
housing enclosing the charging element. The assembly also includes a stop
member mounted to the frame of the machine at a first side of the platen
for contacting a first end of the housing at a desired point so as to
automatically align the start-of-charging position of the charging element
with the document registration position. A resilient force applying member
connected to a second end of the housing automatically absorbs corrective
adjustments to a location of the start-of-charging position of the
charging element relative to the document registration position on the
platen, thereby automatically aligning the start-of-charging position with
the document registration position.
Inventors:
|
Young; David K. (Fairport, NY)
|
Assignee:
|
Xerox Corporation (Stamford, CT)
|
Appl. No.:
|
360900 |
Filed:
|
December 21, 1994 |
Current U.S. Class: |
399/311; 399/107 |
Intern'l Class: |
G03G 015/02; G03G 021/16 |
Field of Search: |
355/219,221,200,210
361/229
350/324-26
|
References Cited
U.S. Patent Documents
2836725 | May., 1958 | Vyverberg | 250/49.
|
2879395 | Mar., 1959 | Walkup | 250/49.
|
3691373 | Sep., 1972 | Compton et al. | 250/49.
|
5324941 | Jun., 1994 | Gross et al. | 250/324.
|
5342942 | Jun., 1994 | Mishra et al. | 250/326.
|
Primary Examiner: Pendegrass; Joan H.
Attorney, Agent or Firm: Nguti; Tallam I.
Claims
What is claimed is:
1. In an electrostatographic reproduction machine having a frame, a charge
holding photoconductive surface, and a document platen including a
document registration position useful for producing copies of documents
without darkened borders or clipped edges, an automatically self-aligning
charging device assembly comprising:
(a) a corona generator for charging the photoconductive surface;
(b) a stop member for contacting said corona generator, said stop member
being mounted within the reproduction machine below the platen and spaced
a predetermined distance from a desired position directly below the
document registration position of the platen; and
(c) a resilient force applying member supported within the reproduction
machine and connected to said corona generator, said resilient force
applying member automatically moving said first end of said corona
generator into contact with said stop member in order to align said
start-of-charging position of said charge dispensing aperture at the
desired position relative to the document registration position.
2. The self-aligning charging device assembly of claim 1, wherein said
corona generator includes a housing defining a first end and a second end
of said corona generator, and having a charge dispensing aperture, said
charge dispensing aperture including a start-of-charging position, and
extending between said first end and said second end of said corona
generator for dispensing charge from said corona generator.
3. The self-aligning charging device assembly of claim 2, including an
adjustable position charge blocking member mounted over said charge
dispensing aperture for defining said start-of-charging position.
4. The self-aligning charging device assembly of claim 2, wherein said
predetermined distance from said stop member to the desired position below
the document registration position of the platen is equal to a length of
said housing from said first end of said corona generator to said
start-of-charging position of said charge dispensing aperture.
5. The self-aligning charging device assembly of claim 2, wherein said stop
member is mounted to the machine frame below the platen, and said
resilient force applying member is supported on a customer replaceable
unit housing for mounting by a customer within the machine.
6. The self-aligning charging device assembly of claim 2, wherein said
resilient force applying member is a compressible spring member.
7. The self-aligning charging device assembly of claim 2, wherein said
resilient force applying member has a first uncompressed position placing
said start-of-charging position within said predetermined distance towards
said stop member, and a second compressed position determined by said
first end of said corona generator contacting said stop member, said
second compressed position automatically aligning said start-of-charging
position for said ccorona generator at the desired position relative the
document registration position of the platen.
8. The self-aligning charging device assembly of claim 2, wherein said stop
member includes means for adjusting a position of said stop member,
thereby increasing or decreasing said predetermined distance from said
stop member to the desired position under the registration position of the
platen.
9. The self-aligning charging device assembly of claim 8, wherein said
adjusting means comprises a threaded shaft portion of said stop member and
a thumb graspable portion of said stop member for manually adjusting the
stopping position of said stop member relative to the desired position.
10. The self-aligning charging device assembly of claim 2, wherein said
housing is mounted below the document platen.
11. An electrostatographic reproduction machine comprising:
(a) a machine frame;
(b) a platen mounted to said frame and including a document registration
position for registering a document to be reproduced without clipped edges
and with clean undarkened borders;
(c) imaging means employing a layer of electrostatic charge and charged
toner particles to reproduce an original image of the document, said
imaging means including a photoconductive surface having an available
predetermined width for holding said layer of electrostatic charge;
(d) a self-aligning charging device assembly for producing said layer of
electrostatic charge onto said photoconductive surface in alignment with
said document registration position on said platen, said self-aligning
charging device assembly including:
(i) a charging element having a start-of-charging position;
(ii) a housing enclosing said charging element;
(iii) a stop member mounted to said machine frame at a first side of said
platen for contacting a first end of said housing to automatically align
said start-of-charging position of said charging element with said
document registration position on said platen; and
(iv) a resilient force applying member connected to a second and opposite
end of said housing for automatically absorbing corrective adjustments to
a location of said start-of-charging position of said charging element
relative to said document registration position on said platen, thereby
automatically aligning said start-of-charging position with said document
registration position.
12. The reproduction machine of claim 11, wherein said stop member is
mounted to said frame of the machine adjacent said photoconductive member
and includes a first end thereof for contacting a second end of said
charging device to stop movement by said resilient force applying member
of said start-of charging position of said charging element to a point
within said predetermined distance.
13. The reproduction machine of claim 12, wherein said stop member is
mounted through said machine frame to a point within the machine, and
includes a second end thereof positioned externally of said machine frame.
14. The reproduction machine of claim 12, wherein said stop member is
adjustable and includes a threaded portion for threaded movement through
said machine frame.
15. The reproduction machine of claim 12, wherein said stop member includes
manipulating means connected to said second end for manipulating and
adjusting a position of said first end thereof relative to said
predetermined width of said photoconductive member.
16. The reproduction machine of claim 11, wherein said housing enclosing
said charging element is attached to, and comprises a component of a
customer replaceable cartridge unit (CRU), said CRU further comprising a
cartridge housing and cleaning components of the reproduction machine.
17. The reproduction machine of claim 16, wherein said housing enclosing
said charging elements is attached externally to said CRU housing.
18. The reproduction machine of claim 11, wherein said charging element
comprises a corona wire electrode.
19. The reproduction machine of claim 1, wherein said housing includes a
charge dispensing aperture extending between the first and second ends of
said charging device.
Description
BACKGROUND OF THE INVENTION
This invention relates to electrostatographic reproduction machines, and
more particularly to such a machine including an automatically
self-aligning charging device assembly.
Generally, the process of electrostatographic copying is executed by first
using a corona generating or charging device to uniformly charge a
photoreceptive member, and then exposing a light image of an original
document, positioned in registration on a platen, onto the charged
photoreceptive member. Exposing the charged photoreceptive member to a
light image discharges the photoconductive surface thereof in areas
corresponding to non-image areas in the original document, while
maintaining the charge on other areas thereof, particularly on the image
areas, thus creating an electrostatic latent image on the photoreceptive
member. The undischarged areas including the electrostatic latent image
are subsequently developed with charged toner particles into a visible
toner image. The toner image is thereafter transferred from the
photoreceptive member onto a copy sheet on which the image is then fused
or permanently affixed in order to provide a hard copy reproduction of the
original document.
The described process is well known and is useful for light lens copying
from an original, as well as for printing documents from electronically
generated or stored originals. Analogous processes also exist in other
electrostatographic applications such as, for example, digital printing
applications wherein the latent image is generated by a modulated laser
beam or ionographic printing and reproduction, where charge is selectively
deposited on a charge retentive surface in accordance with an image stored
in electronic form.
In the any of the above processes, a conventional form of a corona
generating or charging device that can be used is disclosed, for example,
in U.S. Pat. No. 2,836,725 as a basic corotron device. As disclosed, the
corotron device includes a conductive corona generating electrode in the
form of an elongated wire that is partially surrounded by a conductive
shield. The corona generating electrode, or so called coronode, is
provided with a DC voltage, while the conductive shield is usually
electrically grounded and the dielectric surface to be charged is spaced
proximate to the wire. Alternatively, the corotron device may be biased in
a manner taught, for example, in U.S. Pat. Nos. 2,879,395, and 5,324,941
and 5,324,942 which describe a type of charging device known as a
scorotron. In a scorotron, an AC corona generating potential is applied to
the conductive wire electrode while a DC biasing potential is applied to a
conductive shield partially surrounding the electrode. This DC potential
regulates the flow of ions from the electrode to the surface to be charged
so that the charge rate can be adjusted, making this biasing system ideal
for self-regulating systems.
Another type of a charging device that is usable in any of the above
processes is a pin array device that includes a charging electrode which
may be an electrically conductive strip having projections, or scalloped
portions in the form of teeth members. The projections or teeth members
are integrally formed with, and extend from, a longitudinal edge of the
electrode. This type of charging device is disclosed for example in U.S.
Pat. No. 3,691,373 to Compton et al. As shown, this type of corona
generating device may further include a screen and/or an auxiliary
electrode as well as various additional conductive shields for regulating
charging current to control the uniformity of produced charge.
Regardless of the particular type, a charging device when used in an
electrostatographic machine, is mounted spaced from, and axially relative
to the photoreceptive member of the machine. In order not to produce hard
copies of images on sheets with toned or black borders, non-image border
areas on the photoreceptive member must either not be charged by the
charging device, or if charged must then be erased or discharged prior to
development with charged toner particles. "Charging and then erasing or
discharging" such border areas after uniform charging involves additional
use of discharge devices, and is therefore relatively more costly. In
addition, it is also relatively more risky in that more or less border
area than is necessary may be erased, thus resulting in poor quality
images. On the other hand, the relatively less risky and less expensive
alternative which is "not to charge such border areas in the first place",
requires a precise alignment of an edge of the areas to be charged (which
is the same as a position where the charging device starts charging) with
a document registration position or edge on a fixed platen.
Unfortunately, however, due to the effects of manufacturing and assembly
tolerances, achieving such precise alignment normally requires skills not
possessed by an ordinary machine user or customer. This can be more of a
problem in the case of charging devices that are manufactured and provided
along with other components as customer replaceable (cartridge) units or
CRU's that are to be mounted in the machine by the user or customer. In
such cases, the-start-of-charging position of the charging device may or
may not be aligned with a desired image edge position on the
photoreceptive member. In addition, there may be a misalignment created
between the registration position or edge on the platen and such
start-of-charging position of the charging device. The challenge to the
user or customer then is to replace the charging device such that its
start-of-charging position is precisely aligned with the registration
position on the platen, and with a corresponding image edge position on
the photoreceptive member. Failure to achieve such alignment ordinarily
will result each time in an image on a copy sheet of paper that has a
darkened border, or that has a clipped image portion adjacent such border,
either of which is unacceptable.
There is therefore a need to provide for use in an electrostatographic
reproduction machine, a customer replaceable unit that includes a
self-aligning charging device which automatically aligns its
start-of-charging position with a platen document registration position.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, in order to
reproduce an image without a darkened border or clipped edge, there is
provided in a reproduction machine having a frame, a charge holding
surface and a document platen including a document registration position,
an automatically self-aligning charging device assembly for producing a
layer of electrostatic charge onto the charge holding surface in alignment
with the document registration position on the platen. The automatically
self-aligning charging device assembly includes a corona generator having
a start-of-charging position, and a stop member mounted to the frame of
the machine at a first side of the platen for contacting a first end of
the corona generator at a desired position so as to automatically align
the start-of-charging position relative to the document registration
position on the platen. A resilient force applying member supported within
the reproduction machine and connected to a second end of the corona
generator for automatically aligning the start-of-charging position at the
desired position relative the document registration position.
In accordance with another aspect of the present invention, there is
provided for use in a printing machine so as to produce copies of
documents without darkened borders or clipped edges, a customer
replaceable unit (CRU) including a housing for mounting to a frame of the
printing machine and a corona generator having a first end mounted to the
housing and a second end for contacting a stop member within the printing
machine so as to position the corona generator at a predetermined desired
position relative to a document registration position of the printing
machine. The CRU also includes resilient force applying means connecting
the first end of the corona generator to the housing for resiliently
urging the second end of the housing into contact with the stop member
when the CRU is used in the printing machine.
Other features of the present invention will become apparent from the
following drawings and description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the detailed description of the invention presented below, reference is
made to the drawings, in which:
FIG. 1 is a schematic side view of the platen, photoreceptive member and
self-aligning charging device assembly of the present invention; and
FIG. 2 is a schematic view showing an electrostatographic reproduction
machine employing the self-aligning charging device assembly of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
While the present invention will be described in connection with a
preferred embodiment thereof, it will be understood that it is not
intended to limit the invention to that embodiment. On the contrary, it is
intended to cover all alternatives, modifications, and equivalents as may
be included within the spirit and scope of the invention as defined by the
appended claims.
Referring initially to FIG. 2, an exemplary electrostatographic
reproduction machine incorporating the automatically self-aligning
charging device assembly of the present invention is illustrated. The
exemplary electrophotographic machine, for example, employs a
photoreceptive member shown as a drum 10 including a photoconductive
surface 12. As is well known, the photoconductive member can equally be a
suitably mounted belt having a photoconductive surface. The
photoconductive drum 10 is coupled to motor (not shown) for rotation about
a process path in the direction of arrow 16 for advancing successive
portions of photoconductive surface 12 through various processing stations
disposed about the process path.
Initially, a surface portion of drum 10 passes through a charging station
A. At charging station A, a corona generating device 26 such as is
included in the automatically self-aligning charging device assembly of
the present invention (to be described in detail below), charges
photoconductive surface 12 to a relatively high and substantially uniform
potential.
Once charged, photoconductive surface 12 is advanced to an imaging station
B where an original document 28, positioned face down and in accordance
with a fixed registration mark or position on a transparent platen 30, is
exposed to light from light sources, such as lamps 32. Light rays from the
lamps 32 are reflected imagewise from the document 28 thus forming a light
image of the original document 28. The reflected rays are transmitted
through a lens 34 and focused onto a portion of the charged
photoconductive surface 12, selectively dissipating the uniform charge on
impacted areas thereof. As such, an electrostatic latent image
corresponding to the original document 28 is recorded onto photoconductive
surface 12.
Although an optical system has been shown and described for forming the
light image used to selectively discharge the charged photoconductive
surface 12, one skilled in the art will appreciate that a properly
modulated scanning beam of energy (e.g., a laser beam) may equally be used
to imagewise irradiate the charged portion of the photoconductive surface
12 in order to record the latent image thereon.
After the electrostatic latent image is recorded on photoconductive surface
12, drum 10 advances to development station C where a development
apparatus 36, deposits developing material containing charged toner
particles onto the electrostatic latent image. Development apparatus 36
for example may include a single developer roller 38 disposed in a
developer housing 40. The developer roller 38 rotates, bringing the
developing material into contact with photoconductive surface 12, thus
developing the latent image into a visible toner image.
After development of the electrostatic latent image as such, drum 10
advances the toner image to transfer station D. At transfer station D, a
sheet of support material 46 is moved into contact with the toner image by
means of a sheet feeding apparatus 48. Preferably, sheet feeding apparatus
48 includes a feed roller 50 which rotates while in contact with a stack
of sheets 46 to advance the uppermost sheet. The advancing sheet of
support material 46 is moved into contact with photoconductive surface 12
of drum 10 at transfer station D in a timed sequence so that the developed
image on the surface 12 contacts the advancing sheet of support material
46, and is transferred. A transfer corotron 56 is provided for projecting
ions onto the backside of sheet 46 in order to aid in inducing the
transfer of charged toner images from the photoconductive surface 12 onto
support material 46.
The support material 46 is subsequently transported in the direction of
arrow 58 for advancement to a fusing station E. Fusing station E includes
a fuser assembly 60 for heating and permanently affixing the transferred
toner image to sheet 46. Fuser assembly 60 preferably includes a heated
fuser roller 62 and a support roller 64 forming a fusing nip for receiving
and transporting a sheet of support material 46 therethrough. After
fusing, the advancing sheet of support material 46 is moved to a receiving
tray 68 for subsequent removal of the finished copy by an operator.
Invariably, after the support material 46 was separated from the
photoconductive surface 12 of drum 10, some residual developing material
remained adhered to drum 10. Thus, a final processing station, namely
cleaning station F, is provided for removing residual toner particles from
photoconductive surface 12 in preparation for subsequent charging and
imaging as described above. Cleaning station F, for example, can include a
rotatably mounted fibrous brush 70 for physical engagement with
photoconductive surface 12 in order to remove toner particles therefrom.
As shown, the cleaning station F may be provided for example as part of a
customer replaceable unit or CRU 134. CRU 134 as illustrated comprises a
CRU housing 132 enclosing cleaning components, such as the brush 70, and a
cleaning blade 136. In some cases, the CRU 134 may also include the
photoreceptor drum 10 shown mounted on a drum shaft 138 and rotatably
driven in the direction of the arrow 16. The cleaning blade 136 is mounted
on a supporting bracket 140, and the cleaning brush 70 is mounted for
disturbing and removing toner particles from the surface of the drum 10
prior to such surface being cleaned by the cleaning blade 136. A flicker
bar 142 may be included for flicking the waste toner off of the brush 70,
and a square paddle 144 for transporting the waste toner to the rear of a
waste toner sump 146, where an auger 150 may then transport the toner away
from the cleaning area.
The foregoing description is believed to be sufficient, for purposes of the
present application for patent, to illustrate the general operation of an
electrostatographic reproduction or printer machine including the
self-aligning corona generating or charging device of the present
invention.
Referring now to FIGS. 1 and 2, a portion of the electrostatographic
reproduction machine is illustrated as viewed, for example, from the
direction of the arrow E--E. As illustrated, the machine includes the
automatically self-aligning charging device assembly of the present
invention, shown generally as 100. The machine also includes a machine
frame 8A, and the document platen 30 that is mounted to the frame 8A. The
platen 30 includes a document registration position 102 which is useful
for properly registering a document so that it can be reproduced with
cleaned undarkened borders, as well as without clipped developed image
edges. The machine further includes imaging means for employing a layer of
electrostatic charge along with charged toner particles, as described
above, to reproduce an original image of a document. The imaging means
particularly include the photoreceptor or photoconductive member such as
the drum 10. Drum 10 has the photoconductive surface 12 and an available
predetermined chargeable surface-width W1 thereof for holding the layer of
electrostatic charge. According to the present invention, the charging
device assembly 100 is automatically and resiliently self-aligned relative
to the document registration position 102 so as to result in unclipped
edge copies with clean, undarkened borders.
As further illustrated, the automatically self-aligning charging device
assembly of the present invention 100 includes the charging device or
corona generator 26 which has a charging element 104 for charging the
charge holding photoconductive surface 12. The charging element 104 is a
corona generating electrode which for example can be a pin array electrode
as are well known, or a wire electrode. The charging element 104, for
example, a pin array electrode, is ordinarily coupled to a high-voltage
extension member, or provided with a high voltage extension member for
connection to a high-voltage power source (not shown). The charging
element 104 preferably has a charging length W2 approximately equal to the
chargeable width W1 of the surface of the photoreceptor 10.
The charging device or corona generator 26 includes an elongate housing 106
having a first end 110 and a second end 112 defining first and second ends
of the corona generator 26. The housing 106 is mounted within the
reproduction machine, below the document platen 30. The housing 106, as
shown, supports the charging member 104 therein by means of end blocks
108, 109, and partially surrounds the charging element. The elongate
housing 106 is preferably attached to, and comprises a component of the
customer replaceable cartridge unit, or CRU 134. When the charging element
104 is a pin array, the elongate housing 106 may be comprised of side
support members and the pair of end mounting blocks 108, 109 positioned
within a shield support frame. The side support members may comprise
elongate members disposed on either side of, and sandwiching, the pin
array electrode. The side support members thus extend between the end
mounting blocks for supporting the electrode within the conductive shield
or housing 106.
The housing 106 has the first end 110, and the second end 112 that is
positionable towards the document registration position 102 side of the
platen 30. As shown, the elongate housing 106 includes a charge dispensing
aperture 114 extending between the first and second ends 110, 112
respectively for releasing and directing charge from the charging element
104 onto the surface 12 of the photoreceptor 10. The charge dispensing
aperture 114 includes a start-of-charging position 116 for the charging
element 104. The start-of-charging position 116 of the charge dispensing
aperture as shown is defined, for example, by an adjustable charge
blocking member 118 that is mounted partially over the aperture, and
towards the second end 112 of the housing 106.
The automatically self-aligning charging device assembly 100 also includes
a stop member 120 for contacting the first end 110 of the elongate housing
106. The stop member 120 as shown is mounted below the platen 30 to the
machine frame 8A, and is spaced a predetermined distance W3 from a desired
position P1 directly below the document registration position 102 of the
platen 30. The predetermined distance W3 from the stop member 120 to the
desired position P1 is importantly made equal to a length L3 of the
elongate housing 106 from its first end 110 to the start-of-charging
position 116 of the charge dispensing aperture 114. The stop member 120 as
mounted through the machine frame 8A, includes a first end 122 for
contacting the housing 106, and a second end 124 thereof that is
positioned externally of the machine frame 8A, for example. The stop
member 120 as further shown includes means such as a threaded shaft
portion 126 thereof, and a thumb graspable portion 128 connected to the
second end 124 thereof for manually adjusting the stopping position of the
stop member, and thereby increasing or decreasing the predetermined
distance W3 therefrom to the desired position P1. The first end 122
thereof is importantly adjusted and set so as to contact the first end 110
of housing 106 and stop the charging device 26 (i.e. housing 106 with
charging element 104) at the far side of the platen 30 from the document
registration position 102.
The automatically self-aligning charging device assembly 100 further
includes a resilient force applying member 130 that is supported within
the reproduction machine and is connected to the second end 112 of the
elongate housing 106. The resilient force applying member 130, for
example, is shown as a compressible spring member, however, it can equally
be any suitable spring device including pneumatic and hydraulic such
devices. The resilient force applying member 130 as such is useful for
automatically aligning the start-of-charging position 116 of the charge
dispensing aperture 114 at the desired position P1 directly below the
document registration position 102, when the first end 110 of the elongate
housing 106 is contacting the stop member 130. In other words, as
connected to the second and opposite end 112 of the elongate housing 106,
the resilient force applying member 130 is suitable for automatically
absorbing corrective adjustments to a location of the start-of-charging
position 116 of the charging element relative to the document registration
position 102 on platen 30, and thereby automatically aligning the
start-of-charging position 116 with the document registration position
102.
Preferably, the resilient force applying member 130 is supported on the
housing 132 of the customer replaceable unit (CRU) 134 so as to be
replaceable therewith within the machine. As illustrated, without the
advantageous features of the present invention, due to manufacturing and
assembly out of tolerance conditions, the start-of-charging position 116
may have anyone of three different corresponding positions P1, P2 and P3
on the surface 12. Position P1 is, of course, ideal and is that which is
automatically achievable according to the present invention. Positions P2
and P3 are undesirable. Position P2 as can be expected will produce copies
with clipped border areas, and position P3 will produce copies with
darkened or toned borders.
However, as further illustrated, the resilient force applying member 130 is
importantly made to have a first, uncompressed position in which it causes
the housing 106 to intentionally place the start-of-charging position 116
at an undesirable position such as P2 within the predetermined distance
W3. The resilient force applying member 130 is also such as will have a
second, compressed position as illustrated in which it causes the housing
106 to automatically place the start-of-charging position desirably at
position P1. This second compressed position of the spring 130 is defined
and determined by the force applying member 130 automatically moving the
first end 110 of the elongate housing into contact with the stop member
120. The length L3 of the hosing 106 from its first end 110 to the
start-of-charging position 116 is such that compression of the spring 130
by the length L3 will automatically align the start-of-charging position
116 of the charging element at the desired position P1 directly below the
document registration position 102.
A main advantage of the automatically self-aligning charging device
assembly 100 is that the position of the end 122 of stop member 120 can be
preset or adjusted in the machine for a particular batch of CRU's 134 that
include the device assembly 100 with contact end 110. Once the position of
the end 122 of stop member 120 has been adjusted in the machine as above,
the device assembly 100 in each CRU that is subsequently mounted in the
machine as a replacement of a previously aligned CRU therein, will
according to the present invention, automatically set or align the
start-of-charging position 102 to the desired position P1, despite the
presence of any out-of-tolerance conditions in each such device assembly.
It is, therefore, apparent that there has been provided in accordance with
the present invention, an automatically self-aligning charging device
assembly 100 for producing a layer of electrostatic charge onto a
photoconductive surface 12 in alignment with a document registration
position 102 on a platen 30. The self-aligning charging device assembly
100 includes a charging element 104, and an elongate housing 106 enclosing
the charging element and having a start-of-charging position 116 thereto.
The self-aligning charging device assembly also includes a stop member 120
mounted to the frame of the machine at a first side of the platen for
contacting a first end 110 of the elongate housing at a desired point for
automatically aligning the start-of-charging position of the charging
element with the document registration position on the platen. A resilient
force applying member 130 is connected to a second and opposite end 112 of
the elongate housing for automatically absorbing corrective adjustments to
location of the start-of-charging position of the charging element
relative to the document registration position on the platen, and thereby
automatically aligning the start-of-charging position with the document
registration position.
While this invention has been described in conjunction with a specific
embodiment thereof, it is evident that many alternatives, modifications,
and variations will be apparent to those skilled in the art. Accordingly,
it is intended to embrace all such alternatives, modifications and
variations that fall within the spirit and broad scope of the appended
claims.
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